Fish canning control apparatus



Jan. 12, 1965 J. J. SENNELLO FISH CANNING CONTROL APPARATUS Filed March 6, 1962 HOV-60 N 3 Sheets-Sheet l 4.9 FIL L //V6` MACH/NE CAB/IVE?" INVENTOR. JSL-PH J. SEMI/ZL BY MLM #76M Jan. l2, 1965 J. J. sENNELLo 3,154,857

FISH cANNING CONTROL APPARATUS Filed March 6, 1962 5 Sheets-Sheet 2 im L104! /12 ,05

SERVO AMPLIFIER IN VEN TOR. JOSEPH J. SENA/ELLO BY MM ,V/J

Jan. 12, 1965 1.J. sENNELLo 3,164,357

FISH CANNING CONTROL APPARATUS JOSEPH J. SENA/ELLO BY a #Ml by means of rotating feeding fingers.

United States Patent y 3,164,857 4 t FlSH CANNNG CONTROL APPARATUS Joseph J. Sennello, Dak Lawn, lll., assigner to Continental Can Company, Inc., New York, NX., a corporation of New York v Filed Mar. 6, 1962, Ser. No. 177,868 Claims. (Cl. 17-4) The invention relates to the art of fish canning and particularly, to the canning of relativelylarge fish such as tuna or salmon. Y

InV the canning of such fish the common practice in the industryis to use a can filling machine andk a fish cutting machine connected together by a fish delivery tunnel. Dressed fish is fed into a gang' cutterin the fish cutting machine which'cuts the fish into fillets having a thickness slightly less than the height of the cans to be filled. The cut-up fish is then moved into the fish delivery tunnel When the supply of fish in the' tunnel reaches the filling machine the filling machine is vstarted to commence filling cans. With such an arrangement, it is anccessity that the filling machine always belsupplied with a solid stream of fish through the Atunnel so that each of the cans fed vinto the filling machine will be filled to Vthe desired'capa'city. lt is `also of great importance that the tunnel extending between the fish cutting machine and the filling machine does not become oversupplied with fish to the extent that the fish feeding fingers in the fish cutting machine being to compact the fish in the tunnel resulting in the breaking Y the fish tunnel; andV 3,ld4,857 "Patented Jan; 12, 1965 2 Y in response to the amount of fish in the tunnel adjacent to the Unit.

The above and other objects of the invention will be bet-v ter understood by referring to the following description and Y drawings in which:

FIG. lis a side elevation view partly in section, of the fish cutting and filling machines and electrical'and hydraulic components ofthe control and drive system;

`RIG.v 2 is a diagramv of the electro-hydraulic control system;` f Y `FIG. 3 is a side elevation View, mostly in cross-section through one of the electrical detecting heads mounted in FIG. 4 is an end view partly in section of the detecting unit of FIG. 3. f 4 Y `Referring to FIG.' 1 ofthe drawings, it will be seen .that the fish cutting machine is generally indicated by the numeral iti. The can fillin machine is generally iii has Vahorizontal endless belt or chain type of'conveying table 15 onwhich dressed fish'l are placed Vfor up of the solid chunks offish which, if not immediately corrected, could result in the whole lot of filled cans being down-graded resulting in a direct Vmonetary loss when the lot is sold.

Since the filling machine and the sh cutting machine each has its own. individual drive, it has become the well known type in the industry and a detailed description practice inthe industry to regulate, by the best prior art i means, thespeed', of the drive of the fishwcutting machine vin order to attempt to regulate thetspeedtofthe fish cutting operation Ato meet. they exact demands of the filling machine.` Much work has been done in the past inorder to'solve Vthe'problem of coordinating the speed of. theiish L cuttingl machineto exactly meet the demands of thecan,

filling machine; with at best, onlyl a moderate degree of successfpbeing achievedj Perhaps the'main reason for the lack of a practical solution -toy .the problem by the knownprior art meansforlsolving it is that all of such means have beenicomplicated in nature. By complicated is meant thatv manymechanical linkages are used .which are difficult to adjust and'keep adjusted and which eventually develop free play due towear. which is very difficult-to compensate for.

Byway. fof conti-ast, 'the presently disclosedfarrangement-uses a minimum of mechanism and such that is used for the, most partis readily purchased on the open market. v

Accordingly, it'fis'the general object of' the invention to provide. asimplitied andreliable control systeml for controlling the' iiow of. fish in the `fishtunnel extending between the fish'lcutting `machineiand the can fillingl It is a further and more specifico-inject of the invening means; is ofthe hydraulic typel .,It is `a still further andmore specific objectof the i invention to; provide a novel, reliable-and sanitary type of electrically" operated detecting unit" `which mounts in a `wall' of the flsh'tunnclr and generatesan` electrical signal beingconveyed tothe right thereon into the machine where they are cut upt into fillets'which are transferred into the fish tunnel 13by meanso'f rotating feed fingers (not shown): the filleted fish in the fish tunnel'being indicated by the numeral 17. The fishcutting machine, in-

cluding the horizontal fish infeed conveyor table 15 is driven by a hydraulic motor 20, With the exception of the replacement of its usual electric drive motor by the j hydraulic drivev motor 20,l the' fish cutting machine itself is` unchanged. The fish cutting machine depicted is a of the operation thereof is not necessary for the purpose of clearly setting forth the present invention. l

. Thecan filling machine 11 'is alsoyof a standard type in the industry and has its own adjustable speed drive indicated'at 18. Emptycans zljare'fed'd'own a feed chute 22 intov the fillingfmachineby means of gravity.

rl`he cans kare .filled with fish supplied through the tunnel Y 13 and the filled cans pass out of the machine on a horizontal conveyor 23. The speedfof the filling machine is independently adjusted to fill a set number. of cans within a unit `of time vof givenlength. 1.

Af'lfhe'hydraulic pump-and control lunit 14 has a hydraulic fluid'jreservoir 24 on which is mounted a hydraulic pump 25 which has aivariablelvolumetricoutput The pump 25 isl driven by an integrally mounted electric motor 26'. Y Mountedon a support plate A27 onthe reservoirV is a torque 'motor 28 having'an armature 43,1 which has one end ofl an-operating rod32 Vattached thereto. The other end of the operating rod 32 is attached to .the'slidevalve member 39j ofV a -hydraulic servo valve 33,. The hydraulic servovalve 33 is also mounted on theplate 27. Mounted on one side of the hydraulic pump 25 is a Vforce amplifying hydraulic cylinder 34. A control stroking cylinder 35 is mounted in axial alignment with the hydraulic cylinder i 34.; Mounted'on the side of the hydraulic pump 25 opposite hydrauliccylinders 34-and 35, is a linear variable differential transformer generally 36; having an operating i rod 37 The end of the operating rod 37 that projects out of which isfvariedfin responselto signals from the detectthrough a pipe 42 for delivery to the hydraulic The V'high pressure fluid acts to'turn the shaft :44 of thel Y vhydraulic motor. vThe-shaft 44 is coupled `to thednput'; f shaft 45 of the fish cutting machine. by means of Va flexv ible coupling 46. The fluid delivered lthrough line 42,

of the transformer passes through the pump housing 40 and touchingly engages the side of a slideblock 3S; the position of which, within the pump housing, determines the volumetric output rate of the pump.; i-

Fluid fromthe pump 25 is discharged at high v pressure,` motor 20.

upon performing its Work of driving the motor 20, is returned tothe suction side of the pump through a pipe 47. t The hydraulic system is maintained full of fluid by means of a pipe 41 which extends from the suction side of the pump into the fiuid reservoir 24.

The hydraulic pump and control unit 14 is of a standard design; the construction details of which form no part of the present invention; VOne such pump and control unit that is quite similar in construction and operation to the unit 14, is a type AV manufactured by the Oil Gear Co., Milwaukee, Wisconsin, U.S.A. Such an AV pump andvcontrol unit may be purchased complete, including a torque motor simliar to the torque motor 28, a servo valve similar to the servo valve 33, hydraulic cylinders similar to cylinders 34 and 35, a drive motor similar to the motor 26, a linear variable differential transformer similar to the transformer 36, and a hydraulic reservoir similar to the reservoir 24. The hydraulic motor 2i) is also of a type readily purchasable on the open market and is selected to meet the power requirements of the fish cutting machine. The pump' unit is selected as to size and delivery rate to meet the demands of the selected motor. Furthermore, the motor 2G is of a type whose shaft 44 Will rotate at a speed proportional to the volumetric fluid flow rate being delivered to the motor through the pipe 42. Therefore, by varying the volumetric output rate of the pump 25 through the pipe 42, the speed of the motor 29 will be varied accordingly and hence the rate at which fish 16 on the horizontal conveyor table 15 are fed into the fish cutting machine 1t) will be varied accordingly. The feeding; of the fish fillets 17 into the tunnel 13y by the fish cutting machine will also vary proportionately with respect to the speed of the motor 20.

The fish tunnel 13 has an upper wall 50 having openings 51` and 52 therein. Mounted in overlying relationship with respect to the opening 51 isa detecting unit generally indicated at 53. The detecting unit 53 has a vertically movable detecting element generally indicated.

at 54. ln overlying relationship with respect'to the opening 52 is a second detecting unit generally indicated at 55, and having a detecting element generally indicated at 56.

The detecting units 53 and 55 are of similar construction,

the details of which will be described later. "The fish tunnel also has a bottom wall 49 and side walls 59 and The servo control cabinet, generally indicated at 12, isA

suppliedV with a source of alternatingcurrent, such as ordinary 110 volt-60 cycle`hous`eV current through wires 61 and 62. Electrical signals developed by the detecting units 53 and 55 and alsok by the linear variable differential v transformer 36 are directed into the servocontrol cabinet as indicated by the arroWs. Output signals from the servo control cabinet 12 developed in response to the input signals are directed to the torque -motor 28 for the actuation thereof, as indicated by thearrow. The torque motor operates to vary the volumetric output rate of the pump 25 through the pipe 42, and hence operates to vary 11. The detecting unit 55- is located upstream of the iiow of fishclosely adjacent the fish cutting machine..

The operation of the equipment is as follows: when 53 and 55 and transmitted to the servo control cabinet. A responsive signal is generated in the servo control cabinet and is transmitted to the torque motor 28, causing the armature 31 of the torque motor to assume a position which through operating rod 32, servo valve 33, control roliing hydraulic cylinder 35, and force amplifying cylinder 34 causes the slide block 38 in the pump to be moved to a point whereat it will cause a pre-set maximum flow of fiuid through pipe 42 causing the motor 29 to run at a pre-set maximum speed. When the lslide block 38 has reached the point at which it causes the pump to develop its pre-set maximum output, the linear variable differential transformer36, by reason of the movement of the operating rod 37 following the slide block 38, will develop an electrical signal equal to and of opposite phase to the sum of the signals from the detecting units 53 and :S5 such that the three signals when added together cancel eachother. This causes the termination of the signal to the torque motor 2S the armature of which then returns to a neutral position leaving the pump delivering at the pre-set maximum rate. With the fish cutting machine thus running at its pre-set maximum speed, the dressed sh 16 will be conveyed into the fish cutting machine where they will be cut up into fillets and the fillets will be fed into the fish tunnel causing the fish tunnel to begin filling up. As the fillets 17 move along in the tunnel toward the filling machine 11, they begin to stack up one upon the other to fill the full height of the tunnel with fish.

When the fish being moved through the tunnel fills the tunnel to substantially its full height under the detecting unit 53, the detecting element 54 will be caused to move upwardly by the fish until it has reached its full upward position. The detecting element 54 when in its full upward position causes the electrical signal output of the detecting unit 53 to drop to zero. This leaves the opposed phase signal from the linear variable differential transformer 36 substantially double that being generated by the detecting unit 55. Due to' this signal inbalance, a

' responsive signal is developed .in the servo control cabinet YThe fish cutter will thus be caused to run at the predetermined medium speed. When the slide block 38 has arrived at its predetermined medium speedv position the signal-developed by the linear variable differential transi former 36 will be equal to and opposite the signal developed by the detecting unit 55 which effects the termination ofthe signal to the torque motor 28 causing the armature 31 thereof to return to its neutral position leaving the pump 25 delivering fluid at its medium rate.

The filling machine can now be started with empty cans being fed in through the chute 22 and filled cans Vbeing fed out on the conveyor 23. When the fish cutting starting up with an empty fish tunnel the motor 26 for the hydraulic pump is started and dressed fish 16 is supplied to the horizontal conveyor table 15. The servo control cabinet wires 61 and 62 are then energized bythe volt-60 cycle power supply to complete the energization of the control system. Since the fish tunnel is empty, the detecting elements 54 and 56 'will be caused `to extend downwardly to vtheir full downward limit.

When the detecting elements are in this position maximum' output signals are ydevelopedfby the detecting 'units machine is running at medium speed it should closely 'meet the demands of the filling machine for fish. As

ywill begin to slowly fill up to its full height further and further Vback toward the fish cutting machine, until eventually the tunnel will vbe filled to its full height directly under the detecting unit 55 causing the detecting element 56 to be moved upwardly slightly. 'This slight upward movement will cause a proportional slowing down of themotor v20,' caused by a reduction of therma'gnitude of the:l

signal being transmitted from the detecting unit 55 to the servo control cabinet. If the height of the fish still continues to build up under thedetecting unit 55, eventually the detecting element 56 will be moved upwardly to its Vfull extent. Wheninfthis position the signal from the detecting unit 55 is reduced to substantially zero along with the signal from the detecting unit 53 leaving the signal from the linear variable differential transformer 36 unopposed. This unopposed signal causes a signal v to be developed in the servo control cabinet to actuate the torque motor 28` such that the armature 31 thereof will be `actuated to l'assume a position to cause the volumetric output of the pump to dropto the point where the sh cutting machine either comes toy a standstill or is operating at a very low speed. Thefilling machine will now begin using up the fish in the tunnel faster than it is being supplied causing the detecting element 56 to again begin lowering to increase the speed of the fish cutting machine andthe rate of the fish delivery into the tunnel.

If, on the other hand, the fish cutting machine is not meeting Vthe requirements of the filling machine whenthe fish cutting machine is running at the normal medium speed, the height of fish in the tunnel under the detecting unit 53 will diminish causing the fish cutting machine to gradually pick up speed, due to the lowering of element 54,`until the tunnel is again full at this point, which causes the detecting element 54 to again be moved fully upwardly to return the fish cutting machine to its normal medium speed.

A better understanding of the operation of the control system may be obtained by referring to FIG. 2 in which L the control systemis shown in more detail. The ll0 volt-,60 cycle power supply is impressed on the primary winding 57` of a .transformer generally -58 in the servo control cabinetf12 `throughwires 61 and 62'. Wires 63 and 64 are connected to the secondary coil 65 of -the transformerwith the voltage differential between wiresV 63 and 64 being reducedto a suitable voltage forv linear variabledifferential transformer operation. 55 volts have been found to give satisfactoryoperation. Linear Variable differential' Ltransformer 36 hasja primary coil 66- connected to {wire 63 ,bywire' 67 and to`wire'64 lby wire 63. alt` also has-a pair of secondaryvcoils 71 and 72 con- ,nected in s eries opposing by a wire 73.: A wire 74 is connected to coil 71 and al wire -75 is connected tocoil 72.

WirefZS has interposedltherein an adjustable potentiometers76.. `The left` endof the voperating rod 37 has at' tachedmthereto formovement therewith, the iron;core.77 of the transformer 36. -Thesright end 'of the operating rod S17-abuts against the aside of the pump slide` block 38 and is urged'by meansnot shown to 'follow the movement" t of the slide block 38`to ftheleft'or right.` The detecting unit 573 has a linear'variabledifferentialtransformer generally indicated at73ghavingaprimary coil- 81 ,and two secondary coils` 82 and- 83.- ESeconda-ry coils,- 82. and '83 are :connectedin' series opposing by a rwire `84..` Primary coil tllis connectedl to. wire 64by a wire-85 and-to wire 63 `by a. wire. S6. Secondary coil-82V is connected to a mary. coil 95 connectedto wire64V a wire`j96 and to, wire,63 by wire97. a It also has-.a pair of secondary coils 98 Vand 101 connected in kseries opposing byawire i102. Coil 98mis' attached ,toi a wire 103 anda coil 161:is attached to` a'iwire 104 -having interposed therein an Iadjilstabl'e transformer 94.

. ket.

has attached i thereto the Wires 63 and 64 terminate in a servo amplifier 109 and supply power thereto. The servo amplifier 109l is designed and sized to operate the torque motor `23 and is of a standard design readily obtainable on the open mar- A wire 112 connects theftap member 110 of adjust- Vable potentiometer 105 to the servo amplifier 109. Wire 113 connects the servo amplifier 109 with the adjustable ta'py 114 ofthe potentiometer 76.

The torque motor 28 has a pair of center tap coils 115 and 116. `Wires A117, 118 and 121 connect coil 115 to the servo amplifier V169. Wires 122, 123 and 124 connect coil 116 to the servo amplifier 169. The armature 31 of the torque motor 2S is pivotably mounted on apin 125. The left end of rod 32 is connected to the armature and force amplifying cylinder 34 respectively.` The control stroking cylinder 35 hastherein a movable piston 123 having on oneside thereofV a piston rod 129. The right i end of piston rod 129 has attached thereto aspool valve potentiometer generally .1075. Wires 103 and"`104"are" connected by meansrof a wire 106 tothe adjustable'tapl lofthepotentiometer'91.lv The detectingelement fleft and center 13). Cylinder 35 has at one end a uid pipe 132 and at the other a fluid pipe 133. Fluid pipes 132 and 133 are connected to-passages 134 uand 135 respectively in the Y valve block 30 of the valve 33.' Passages 136 and 137 in valve block 36 connect toda pipe 138 that returns to a the reservoir 24. The slide valve 39 has internal ports 141 and 142. Valveblocklili also has a passageway g 143 communicating the pipe 126 with the slide valve 39,4

',The force amplifyingfhydraulic cylinder 34 has a piston 144 which has attachedon the right side thereof a hollow piston rod 145. The end ofthe piston rod 145 abuts the pump slide VblockA 38. VThe slide block 38 is alwaysurged toward the left by hydraulic meansl within the pump, such that iffn'o fluidV pressure s exerted on the leftwhand side` of the piston 144, thefslide'block will be caused to move to the` full extent of, its travelV to the left.. When, however, hydraulic pressure is applied :on `the left hand side A ofthe piston 144, the force applied by piston rod4145 against the slide block 38 .will `override the biasing'force of the slide block 38 to the left and the slide block will be caused to move to a position to the right. Hydraulic fluid li'sV supplied to the spool valve 130 fromA pipe -127 vthrough a port 146 in the piston 144.. The piston 144v 1s` further ported in such a manner thatif the spool valve is movedto` the left,` Vthe `"piston will follow it to the itself with rspec'tftlo the spool valve in its new position. .v If the spool valve is conversely.moved to the right, the piston willagain follow the spool valve to thejright andi center itself again A`with respect tojthe spool vvalve inthe new positiontothe right. In thisf manner the position of the piston 144 is controlled bythe positioning ofthe `spool valve`130l-by the piston rod 129. i InY operation; as Vthe slide Valve 395is'inoved toward the??v right by the rod' 32,-'theport 1,41 is communicated with passages 134 and 143- toisupply hydraulic fiuid from pipe 126 through pipe ,'132tov move the piston 12810 the right. At the sametim'elthe port 142 is connected with passages and 137 so that the hydraulic -fiuid onrthe right side ofpiston 12S can be exhausted back tothel reservoir through pipes 133`-and 138. As the piston 128 and the piston rod 129 move to the right,the spool valve- 130 will move to the right and they piston'144 inf'ollow# ,ing the spool valve will also move tothe fright.. `The 70..

li locl r38 moving it`to the right, themovement of which` towardy the right` causes the volumetric output rate of the If,on they other hand, the operat- Y be moved to the left by the arma# piston rodn145 will,V therefore,i exert pressure on the slide pump .25' to increase. ing rod 32 is `caused to ture 31`the slide valve 39' will have its port 141 in commovable iron core 108l 4of .the i munication with passageways 134 and 136 and the port 142 in communication with passageways 135 and 143. This Will cause the piston 128 to be moved to the left and asa consequence, the piston 144 will also move to the left in following the movement of the spool valve 130. The movement to the left of the piston 144 is brought about by the biasing pressure of the slide block 38 to the left against the end of the piston rod 145. As the slide block 38 moves towards the left, it causes the volumetric output rate of the pump to steadily decrease,`until when the slide block is all the way to the left as far as it will go, the output of the pump is either zero or a very small volume rate. In actual operation of the apparatus, the piston 128 will be shifted only slightly either to the right or to the left from the position shown to effect the increasing or decreasing of the volume rate of the pump 25.

The potentiometers 91 and 105 are adjusted so as to utilize only a portion of the full voltage developed in the secondary circuits of the transformers 78 and 94, respectively, which is generated when the detecting elements 54 and 56 are in their lowermost position as viewed in FIG. l or in the dotted line positions in FIG. 2. With detecting elements 54 and 56 in the dotted line positions, potentiometers 91 and 185 can beadjusted to produce equal signal voltages of the same phase which are added together algebraically and impressed on the secondary circuit of the transformer 36. The core 77 of the transformer 36 is movable within the transformerV between positions such that the voltage induced in the secondary circuit thereof is always 180 out of phase with the voltage being supplied from potentiometers 105 and 91 through wire 92. The resulting induced voltage output is the algebraic sum of the voltages tapped off of potentiometers 195, 91 and the induced voltage in the secondary circuit of transformer 36 which is tapped off in a desired amount by the tap 114 of the potentiometer 76 and transmitted through Wire 113 to the servo amplifier 189. If the sum of the voltages from the linear variable differential transformers 78 and 94 isv greater than the voltage produced by the linear variable differential transformer 36, the command signal resulting from the algebraic addition of these voltages transmitted through Wire 113 to the siervok amplifier will be of one phase. If, on the other hand, the sum of the voltages from the variable differential transformers 78 and 94 is less than the voltage produced by the variable differential transformer 36, theresulting command signal; upon the addition of the three voltages algebraically; which is delivered by` wire 113 into theservo amplifier willl be of an opposite phase.

Whenever the sum. of the voltages produced by the transformers 78 and 94is greater than that produced by` the transformer 36 the resulting phase of the command signal through wire 113 to the servo amplifier 109, will resultA in a direct current voltage being impressed across L Wires 118 and 112 andwires 123 and 124 which, in turn,

transformers 36, 78 and 94 cancel each other out completely, no command signal will be impressed on wire 113 and the armature 31 of the torque motor 28 will remain in a neutral position in which fluid flow into or out of thehydraulic cylinder 35 is prevented, which results in piston 128 remaining in a fixed position. This results in the slide block 38 remaining stationary and the delivery of fluid through the pipe 42 being at a constantvolume rate dependent upon the location of the slide block 3S.

At the start of a can filling operation with the fish tunnel empty, the detecting elements 54 and 56 will be extended downwardly to their full extent with respect to the FIG. l showing, or, to the dotted line positions of FIG. 2. This will cause maximum voltage signals to be produced in transformers '78 and 94, which signals are added and impressed on the secondary circuit of the transformer 36. If, at this time, the slide block 38 is positioned in the place where it causes the pump to deliver. fluid at the maximum pre-set rate, the operating rod 37 in following the slide block 38 will have positioned the core 77 of transformer 36 at the point where the voltage induced in the secondary circuit of transformer 36 will be exactly equal to and of opposite phase to the sum of the voltages from transformers 78 and 94 such that the voltages will cancel each other out and no command signal Will be impressed on Wire 113 to change the delivery rate of the pump 25. Consequently, the pump 25 will deliver at the desired maximum pre-set rate. If,

'on the other hand, the slide block 32 at the time of start up was positioned too far to the left, with respect to its showing in the lower right hand corner of FIG. 2, or too far to the right with respect to the fragmentary piece of the slide block shown in the upper right hand corner of FIG. 2, the addedl voltages from transformers 78 and 94 Will be greater than the opposite phase voltage produced by the transformer 36, such that a command voltage Will appear in Wire 113 to cause the servo amplifier 109 to position the armature 31 of the torque motor 28 to its speed up position which Will result in the .shifting of the slide block 38 until it is shifted to the position where the pump will deliver fluid at the maximum pre-set rate. When the slide block 38 arrives at this position, the core 77 in transformer 36 will be so positioned that the command signal to the servo amplifier will drop to zero due to the voltages produced by transformers 78, 94 and 36 cancelling each other out. Thearmature of the torque motor 28 will then return to a neutral position which results in the fluid delivery rate of the pump remaining will be in the solid line position and the element 56 willv be in the dotted line position; no voltage will now be will'cause the armature 31 of the torque motor 28 to rotate in a clockwise direction about Athefpivot pin 125.

This causes the operating rod 32 to move to the right in which direction of movement .the delivery rate of the pump 25V is caused to increase; which increases the speed of the motor 20 and the fish cutting machine 10 as .explained before. of the voltages from transformers 36, 78. and 94 results in the voltage of transformer-36 being larger than the combined voltages of transformers 78 and 94, the-resulting command voltage in wire 113 being of an opposite phase, will cause Athe servo amplifier 109 to produce a direct current voltage across Wires 117 and 118 and 122 and livery rate of the pump 25'. Whenever the voltages from If, on the other hand, the algebraic sum..

produced by the transformer 78 leaving only the voltage from transformerv94 to`oppose the voltage produced by the transformer 36. Since the pump 25 was just previously operating to supply fluid to motor 20 at a maximum ratel the core 77 of transformer 36 Was positioned to produce a voltage in the secondary circuit of transformer 36 equal and of opposite phase to the combined maximumV voltagesiutilized from transformers 78 and 94. By thus dropping out the voltage produced by the transformer 78, they voltage produced by the transformer 36 will override that produced by the transformer 94 causing a command signal being produced rin Wire 113 to servo amplifier 109 of a phase which results in the slide block 38. being moved toward the point where it causesV where it causes the output ofthe pump to be at the desired medium rate, the core 77 of transformer'36` will have moved from its Vmaximum voltage output position to its 9 new position at which it will cause the transformer 36 to have an output Voltage just equal to and of opposite phase to the lone output from the transformer 94; which causes the termination of the command signal inthe wire 113y resulting inthe volumetric output rate of the pump remaining constant at the predetermined medium rate.

If the fish tunnelnow becomesfull to the eX-tent that both detecting elements 54,a.nd 56 are in their uppermost positions as viewed in FIGURE 1, or both in the solidf line positions as shown in FIGURE 2; transformers 78 and94 will have no voltage output signal: leaving the output Isignal from the transformer 36 unopposed and impressed on wire 113, where it will continue to be impressed in diminishing value as the slide block 38 is moved to the posi-tion where it will cause the `output of .the pump to drop to either zero or a very small minimum value. When the slide block reaches this position, the operating rod 37 of the transformer 36 will have positioned the core 7,7 to the position Where the transformer 36 output signal drops to zero. When this position is reached, no further command signal will be impressed on'wire 113 and the armature of the torque motor 28 will lassume a neutralposition leaving the slide block `38 fixed in the position of zero or minimum pump output. This results in the sh cutting machine either discontinuing feeding Vmore fish into the tunnel, or feeding the fish at a very low minimum rate. The filling machine, shortly thereafter, will have used sutiicient fish to cause the detecting' element 56 to drop back to its normal down position and cause the fish cutting machine toV again return to its and.55, will result in...the vfish. cutting'. machine. having one or more additional medium speeds between which it will operate during thernormal can filling operation.

Further, in accordance with the invention, the ,detect- A ing units 53 and 55 are of novel construction, the details of Which will best be understood by referring to FIG- j URES 3 and 4. Since the units 53 and 55 are identical,

only a description of the unit 53 will be necessary. A block 147 mounts in the opening 51 in the upper wall 50 of the fish tunnel 13.v The block 147 is secured to the wall 50 by means of threaded fasteners 148. VThe block 147 has a large vertical bore 150. that is threaded at the upper end thereof. At the bottom of the bore 1570 and concentric therewith is a smaller bore 151 that is bushed with a suitable bearing material. "A round rod portion 152 of the detecting element 54 is slidably mounted at itslower end in the bushed bore 151.v `At its upper end, the rod v152 is slidably mounted in an adjustable bushing 153. The bushing 153 is threaded at 154 to engage the .threads of the bore 150 for vertical adjustment of the bushing 153 in the bore 150. The bushing153 has`a bore Y A155 which forms a pocket in Which theupper end of acompression spring 156 is seated. The rod 152 is formed from two separate alignedpieces that are threadably conrod portion 162 is a washer 163 against which-the bottom of the spring 156 rests. The spring 156 urges the rod 152 downwardly with the downward extent of movei ment of the rod 152 being limited by the undersurface of the washer 163 contacting the bottom surface of the bore 150. In order to seal the unit `53 fromibeing fouled byv particles of ish enteringthe unit, a rubberboot 164 is placed over the undersurface of the shoe 161. The boot Y it is to be understood that various modifications of the 164 has a vertical circumferential `wall 165, the outer surface of which is held tightly sealed against the periphery of the openingSl by a 4circumferential ring 166.r Ring 10 Y 166 is securely held in place in a recess in the bottom surface of the block.147 by'means of threaded fasteners 167. The shoe 161 loosely slidablyfits into Vthe inner peripheral opening of vthe ring 166. The opening being designated at 168, when the shoe 161 is in its lowermost position, as shown; the generally horizontal wall 170 of the boot 164 will be stretched tight on the undersurface of the shoe. When the shoe 161 is in [its uppermost position, in which position the top surfaceof the shoe immediately surrounding the bottom portion 158 of the rod 152 is in abutting contact with the bottom surface 169 of the block 147, the wall 170 of the bootwill be substantially in a at plane and the boot will be in` only a lightly stretched condition. The pressure of the. spring 156 is adjusted by means of the adjustable bushing 153 to just overcome the tension of vthe boot .so that the wiasher.163 will seat in the bottom of the bore 15,0 whenever there is no iish in the tunnel under the bootof such height that theiish touches the boot. A vertical mounting bracket 169-is mounted by means of threaded fasteners 171 to `the mounting block 147. Linear variable differential transformer 78 is mounted onto brackety 169 by means of threaded fasteners 172. The transformer housing 173 is.

I provided with an aperture 174 that is in aXial alignment 25 with the rod 152. The iron transformer core 93 is movable within the aperture 174. A connecting rod 175 is threaded at its upper end into the lower end of the transformer core 93 and at its lower end into the upper end of the rod 152. The position of thecore 93 can be adjusted within the housing 173 by changing the depth in which the connecting rodV 175 is threaded into the rod 152. A protective cover 176 fits over the transformer 78 and is attached to the block 147by threaded fasteners 177. TheV core 93 is adjusted by means of the rod 175 so that when Ythat communicates-the opening 168 with the interior of the cover 176. It will be yappreciated that the boot 164 may be fabricated from either natural or synthetic rubber or from Vother resilient plastic materials, the main criterion being that the material be sufficiently elastic and strong for the purpose and ybe sanitary, easily cleaned, and not impart an objectionable flavor to the iish.

For ease of description; the operation has been described with detecting elements 54 and 56 in extreme positions Ibut it is to be realized that when the detecting elements are in positions intermediate to those extreme positions described, intermediate command signals will result in intermediate machine speeds. Thus, within the range of control, infinitely variable speed adjustment is obtained in conformance with the position of the detecting elements. l

It is` also to be realized that the degree of control related to each of the detecting'elements need not be4 equal, but can be proportioned Ias required to function as desired. Y From the foregoing description which is limited to the explanationof the operation of `one form, of the invention,

invention will become apparent to those skilled inthe art; therefore, the full scope of Vthe invention is set forth in the .appended claims.

I claim: u

1. In a fish cutting and canning operation in which is provided a iish cutting machine, a fish canning machine and a generally horizontal fish delivery tunnel for delivering cut up sh from the sh cutting machine to the fish ficanning machine;Y the improvement comprising: a'first detecting means in the tunnel vat a point remote from the i fish cutting machine and close to the fish canning machine; a second detecting means in the tunnel at a location closer t to the cutting machine than the first detecting means, each detecting means being operable to assume a first position not substantially filled to capacity with fish and operable to assume a second position when the tunnel at the location of the detecting means is substantially filledA to capacity; control means responsive tothe position of each detecting means, and; a variable speed drive means for driving the fish cutting machine, thespeed of which determines the rate at which the fish cutting machine delivers cut up fish to the fish tunnel, said control means being operatively connected 4to said variable speed drive means to vary the speed of the drive means in response to the position of each of the detecting means.

2. Claim 1 in which the variable speed drive means is controlled to run at a pre-set maximum speed when both detecting means are in the first position; at a pre-set medium speed when the first detecting means is in its second position and the ysecond detecting means is in its first position, and; at a still lower speed when both detecting means are in the second position.

3. In a fish cutting and canning operation in which is provided a fish cutting machine, a fish canning machine, and a fish delivery tunnel for delivering cup up fish from the fish cutting machine to the fish canning machine; the improvement comprising: a first opening in an upper wall portion of the fish tunnel through which is positioned a vertically movable shoe member of a'first detecting unit, said first opening being remotely located from the fish cutting machine and closely located with respect to the canning machine; a second opening in the upper wall portion of the fish tunnel located in a direction toward the fish cutting machine from the first opening, and having positioned therethrough a vertically movable shoe member of a second detecting unit; each of said shoe members being resiliently urged downward into the tunnel to a first position and being upwardly movable to a second position by fish in the tunnel building up to a ysufiicient height at the location of the shoe member to substantially fill the tunnel at that location; each of said shoe members being operatively connected to an electrical signal generating l2 device with the magnitude of the signal generated being proportional to the vertical position of the shoe member; control means for receiving signals from the `signal generating devices; a variable speed'hydraulic motor for drivf ing the fish cutting lmachine and varying the rate of delivery of cut up fish from the fish cutting machine into the fish tunnel, and; electrically controlled variable delivery hydraulic pump means for varying the speed of the hydraulic motor in response to an electrical command signal generated in the control means in accordance with the position ofthe shoe members.

4. Claim 3, in which; when the shoe member of the first detecting unit is in its first position, extending downwardly into the fish tunnel, and the shoe member of the second detecting unit is also inV its first position, the electrical signal generating device 'operatively associated with each shoe member will transmit a signal to the control means, which in turn will transmit a responsive signal to the electrically controlled variable delivery hydraulic pump means to cause the variable speed hydraulic motor to run at a pre-set Amaximum speed: when the first shoe member is in its second position and the second shoe member is in its firsty position the hydraulic motor will be caused to run at a predetermined medium rate speed, and; when both shoe members are in the second position, the hydraulic motorwill be caused to. run at a pre-set minimum speed.

5. Claim 4 in which the electrical signal generating device operatively connected to each shoe member is a linear variable differential transformer.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A FISH CUTTING AND CANNING OPERATION IN WHICH IS PROVIDED A FISH CUTTING MACHINE, A FISH CANNING MACHINE AND A GENERALLY HORIZONTAL FISH DELIVERY TUNNEL FOR DELIVERING CUT UP FISH FROM THE FISH CUTTING MACHINE TO THE FIST CANNING MACHINE; THE IMPROVEMENT COMPRISING: A FIRST DETECTING MEANS IN THE TUNNEL AT A POINT REMOTE FROM THE FISH CUTTING MACHINE AND CLOSE TO THE FISH CANNING MACHINE; A SECOND DETECTING MEANS IN THE TUNNEL AT A LOCATION CLOSER TO THE CUTTING MACHINE THAN THE FIRST DETECTING MEANS, EACH DETECTING MEANS BEING OPERABLE TO ASSUME A FIRST POSITION WHEN THE TUNNEL AT THE LOCATION OF THE DETECTING MEANS IS NOT SUBSTANTIALLY FILLED TO CAPACITY WITH FISH AND OPERABLE TO ASSUME A SECOND POSITION WHEN THE TUNNEL AT THE LOCATION OF THE DETECTING MEANS IS SUBSTANTIALLY FILLED TO CAPACITY; CONTROL MEANS RESPONSIVE TO THE POSITION OF EACH DETERMINING MEANS, AND; A VARIABLE SPEED DRIVE MEANS FOR DRIVING THE FISH CUTTING MACHINE, THE SPEED OF WHICH DETERMINES THE RATE AT WHICH THE FISH CUTTING MACHINE DELIVERS CUT UP FISH TO THE FISH TUNNEL, SAID CONTROL MEANS BEING OPERATIVELY CONNECTED TO SAID VARIABLE SPEED DRIVE MEANS TO VARY THE SPEED OF THE DRIVE MEANS IN RESPONSE TO THE POSITION OF EACH OF THE DETECTING MEANS. 